That's the nature of business these days, but it's always been that way to an extent. 20 years ago, when I was specifying components for SONY designs I had parts suppliers calling me and offering me things I won't even mention on a public forum, if I would specify their parts for SONY products. They all wanted to establish a "relationship" with me. A week after I left SONY I couldn't even get a call-back from any of them. The more things change, the more they stay the same. That being said, things are tightening up at almost every company.
Companies like Tek and (HP/Agilent/Keysight) no longer include schematics and service info in their manuals, nor will they even sell you a service manual. Thanks to bean-counters, it has gone from the traditional "techies helping techies" to an absolutely adversarial relationship between supplier and customer. Then after you've bought their high priced $20,000 gear and it needs repair they tell you the product is "no longer supported," and they won't fix it for any price, or provide any info about it even though they no longer sell it, and tell you to buy the new model for twice the price.
I'm just glad I can still provide a company name and still get sample parts from most IC manufacturers. I should see if I can snag a couple of these LTC2644's to play with.